Finding X-Dimension

[Donskihp]

When trying to re-prop, I'm getting too much transome lift. Apparently my Donzi is set up from the factory with a very high X-dimention. The more pitch I go the more transome lift I get. But I'm still smashing my revlimiter. I'm thinking I need to add a drive spacer. My hull is 2 stepped and the transome is stepted. Exactly where do I measure to find the correct X-dimension? Don

 

[MOBILEMERCMAN]

The X is a mark made to cut the hole in the transom. It is where the horizontal crank shaft center line crosses the vertical center line on the transom.

X dimension numbers don't help much once the boat is rigged.. Parallel the prop shafts to the bottom and measure prop shaft centerline to bottom with a long straight edge. This will be a more useful measurement to work with.

 

[Donskihp]

What are normal X dimensions compared to a high one? Don

 

[jeffswav]

Like was said before by Jim, the x dim is the measurment from the crankshaft centerline to the bottom of the boat. The propshaft centerline is the measurment from the bottom of the boat to the center of the propshaft. I recently raised my engine and drive up 3". My propshaft is now 5" deep. Most of the performance boats are now leaving the factory in this range. Get the drive as level as possible and take a measurement from the bottom, you will need a straitedge, I used a 4' level.